The two currents then moved into the bay and created tremendous forces, which eroded the coastal area.
Jakarta National Research and Innovation Agency (BRIN) researcher Widodo S. Pranowo on Saturday listed a number of factors that likely caused the recent abrasion on Amurang Boulevard Beach, South Minahasa District, North Sulawesi Province.
In a statement received here on Saturday, he said that the geographical condition of the beach, which directly faces Sulawesi Sea, could have created a bay and caused refraction.
“Refraction is when a wave moving toward the beach undergoes a change in its crest line. Later, the wave moves parallel to the contours of the shoreline,” he informed.
Another factor that can have caused the abrasion is the hydrodynamic force generated by two kinds of currents moving around the bay, he said.
The first current generated by tidal waves may have moved toward the northeast of the bay, while the second one produced by wind and ocean waves may have moved toward the west.
“The two currents then moved into the bay and created tremendous forces, which eroded the coastal area,” the researcher said.
According to tidal data recorded between 1 p.m. and 5 p.m. Central Indonesian Standard Time (WITA, UTC+8) on June 15, 2022, the sea level elevation at Labuhan Uki Station was observed to be higher compared to Manado Station.
Source: Antara News